The invention relates to a method for checking the functional capacity and operating characteristics of semiconductor components.
This application claims the benefit of the priority date of German application 101 15 280.9, filed on Mar. 28, 2001, the contents of which are herein incorporated by reference.
Semiconductor components are tested with respect to their functional capacity. When the elements are being tested, both the temperature of the test environment and the maximum achievable operating speed of the semiconductor component are measurement parameters. In a first step, the so-called xe2x80x9clow temp programxe2x80x9d, at a low temperature of e.g. xe2x88x9210xc2x0 C., the semiconductor components are allocated to various categories with respect to their maximum achievable operating speed at the low temperature, and are distributed, in a handler, to various bins (containers). In this way, a plurality of bins with different speed classes are produced. The total number of all the semiconductor components distributed throughout the various bins may in this case lie between 5000 and 20,000.
In a second step, the various bins of semiconductor components are delivered individually to a xe2x80x9chigh temp program.xe2x80x9d In the xe2x80x9chigh temp program,xe2x80x9d they are re-tested with essentially the same procedures as in the xe2x80x9clow temp program,xe2x80x9d but this time at a higher temperature of e.g. +85xc2x0 C.
At the end of the two measurement procedures, the components are divided up into speed categories, with the components of a given category achieving a particular operating speed throughout the temperature range.
A disadvantage of this prior method is that the sorted components must not be mixed again after the low temp measurement. This entails considerable logistical complexity, since the individual bins need to be transported independently of one another, intermediately stored and tested separately in the xe2x80x9chigh temp program.xe2x80x9d Furthermore, one container needs to be disconnected and another needs to be connected up each time a new bin of semiconductor components is being docked to the test station for testing at a higher temperature. This results in a longer loading time for the handler and extra work for the operator. Furthermore, it is not possible to preclude the possibility that the individual bins may mistakenly be interchanged when an operator intervenes in the process.
It is an object of the invention to provide a method which obviates the need for transportation and intermediate storage of semiconductor components that differ from one another only in terms of their maximum achievable operating speed, and which permits sorting of the components without human intervention.
The basic concept for achieving the foregoing object is to sort the components only logically according to speed classes in the xe2x80x9clow temp program,xe2x80x9d without physically separating them from one another As a result, all the components are contained in one bin afterward, just as they were before. The distinction between the components is made by using information that is saved for each individual component in a file during the first test procedure, the xe2x80x9clow temp program.xe2x80x9d The main aspect of the information about each component is the speed class to which it belongs. In addition, it is possible to store other parameters of the test measurement, such as e.g. the bin number, measuring instrument and the temperature. The file with the information about the different speed classes is saved on a server. The correlation between the data in the file on the server and the individual component is made possible by using the identification of the component. This identification is programmed into the component in a way that precludes erasure or alteration, and which is likewise stored in this file. During the xe2x80x9chigh tempxe2x80x9d program, the file is imported and compared with the currently read chip identifications of the components. The information relating to the speed classes of the components from the xe2x80x9clow temp programxe2x80x9d and from the xe2x80x9chigh temp programxe2x80x9d is subsequently combined, and only then are the components physically sorted.
The method on which the invention is based for classifying components includes recording a maximum achievable operating speed of each component at at least two temperature values, and allocating each component to a speed category as a function of the operating speed achieved by the component at the at least two temperature values.
In some practices of the invention, the following steps are carried out: reading the identification for each component, storing the operating speed achieved at a first temperature value in conjunction with the read identification for each component as an entry in a file in a database, repeating the preceding step for each further one of the at least two temperature values, and allocating each component to a speed category as a function of the operating speeds stored in the file in the database.
Preferably, the first of the at least two temperature values is the lowest temperature value, and each of the subsequent temperature values is higher than the temperature value preceding it.
In a preferred embodiment of the invention, the allocation of the component to one of the speed categories is carried out by determining the minimum of the operating speeds achieved at all of the at least two temperature values.
Other features and advantages of the invention are disclosed in the following description of a preferred exemplary embodiment.